UPPER EAST SIDE — In 1983 art dealer Jack Tanzer was certain he had bought a diamond in the rough — an oil painting he believed was by the 16th century Italian artist Michelangelo Merisi da Caravaggio.
The painting bore a strong resemblance, both in appearance and quality, to "Supper at Emmaus," one of Caravaggio's acclaimed works that showcases his mastery of light and shadows.
But even as it passed from one wealthy collector to the next during the 1900s, Tanzer's acquisition had never been authenticated. Naysayers pointed out that this painting had not been securely documented during the artist's lifetime and dismissed it as a copy by one of his contemporaries. They also noted that it was signed, and Caravaggio had rarely put his autograph on works.
Seized by the painting's excellent condition and high craftsmanship, Tanzer remained convinced of its origins. And if true, it meant a price tag in the tens of millions of dollars.
So the Upper East Side dealer spent the last two decades of his life trying to prove the painting was the real deal. When he died at 83 on Feb. 7, 2005, the authenticity was still in question, but his pursuit was alive and well.
After Tanzer's death, Warren Adelson, an Upper East Side gallerist and friend, took up the crusade. Adelson also owned a 25 percent stake in the painting and shared in the belief it was a bona fide Caravaggio.
After being named the executor of Tanzer's estate, Adelson began spending considerable — if not too much — time and resources on the painting's origins. By 2011 he had poured $500,000 into the painting's conservation, insurance and research to prove authenticity, prompting Tanzer's son to say enough is enough.
That year Edward Tanzer filed a petition in Manhattan Surrogate's Court demanding Adelson's removal as executor. The painting was still unsubstantiated and the quest had gotten in the way of Adelson administering Tanzer's father's estate, namely transferring over a $485,000 Westchester county condominium left to Edward, according to the court filing.
"The efforts and finances expended by Adelson to authenticate the painting have not been reasonable and have caused the continuing postponement of the distribution of the estate," Edward Tanzer said in the petition.
In a subsequent filing last week, he accused Adelson of failing to provide an accounting of the estate assets as ordered by the court.
Adelson has responded in court filings that he can't transfer the condominium to Tanzer because the estate has outstanding debt. Adelson includes himself among the creditors, claiming he is owed 75 percent of the $500,000 spent on the painting's authentication.
Adelson, who also owns an Upper East Side gallery, said that Jack Tanzer had entrusted him with having the painting appraised and sold at the proper amount.
In defending the steep costs expended on the painting, he argued that swaying the opinion of art historians is important, but so is the use of recently developed science and technology like X-rays and other imaging devices that can reveal an artist's creative process. While the price was high for these tools, the pay off could be huge, Adelson said.
"[Adelson] believes that achieving such attribution of ownership will produce such a substantial benefit to all persons interested that the expense will be more than justified," he said in court papers.
Because of his exquisite talent and modest output, Caravaggio's paintings are rare and highly coveted. In 1987 one of his early paintings, "The Card-Sharps," sold for $15 million.
"Supper at Emmaus," which depicts a resurrected Jesus Christ revealing himself to two disciples, hangs in London's hallowed National Gallery.
At 56 by 72 inches, Tanzer's painting is slightly bigger than that painting. In an appraisal commissioned by Adelson, art historian Robert Simon described Tanzer's piece as "a close version of one of the artist's most celebrated canvases" and that it "is an impressive and imposing work and one that from all appearances would date from the beginning of the seventeenth century."
Simon notes that one distinguished art scholar believed the painting was the work of a Caravaggio collaborator, but more recently attributed it to the artist himself. He also states that research shows Caravaggio did make several copies of paintings and autographed some replicas, lending support to Tanzer's piece.
Other scholars have dismissed Tanzer's painting or not publicly weighed in, according to Simon's appraisal.
He notes that without scholarly consensus, he must hedge the valuation.
If it were authenticated, the painting would easily fetch tens of millions of dollars at auction. But since its authorship remains in doubt, Simon placed the current value at $800,000.
The appraisal also makes a tantalizing argument for Adelson to continue his crusade, noting, "Advances in scholarship and changing standards of connoisseurship might well result in a reassessment of the painting's authorship in the future."